Heretofore in the general field of the invention it has been known to pass a series of objects along a first conveyor such that one or more workstations could perform selected operations on the object as it traverses the conveyor. Similarly, packaging apparatus or painting apparatus are sometimes variably positionable relative to objects moving on a conveyor, however, for the most part, devices known to me have utilized some form of mechanical coupling or some timing functions to correlate the movement of the devices relative to one another. Such devices are exemplified in the following U.S. Pat. Nos. 3,587,087; 3,283,918; 4,673,075; 4,870,921; 4,924,996; and 4,842,123.
In the automotive industry, the improvements in automation and testing during assembly continue to require new labor saving and quality improving features. One such improvement involves electronic testing of the electrical systems of the automobile. It is possible to connect an electronic testing device to predetermined terminals in the partially completed vehicle assembly and perform, within a reasonably short period of time, a plurality of tests and checks to insure the integrity of the system. Familiarity with the automation of the industry reveals that although such testing may be performed in a short period of time, the continual process of building automobiles is significantly hampered if this testing step requires the automobiles to stop and thus accumulate while the testing is performed. This is certainly true in other automated fields of endeavor, however, the automotive field is the most familiar. In some applications it is important to be able to contact the object such as an automobile with a testing mechanism or the like, but without thereby affecting the movement of the object along a predetermined path. It is also desirable to move the testing mechanism concomitantly with the object under test without any physical connection to insure such concomitant motion. This is particularly true where no readily available connecting means are present which can be attached to the tester and the object while they are moving without some danger or complexity. Accordingly, there exists a need for an automated system that will move a test unit or workstation concurrently with an object on an independent transport means without the necessity of mechanical connection therebetween.